--[[
The MIT License (MIT)

Copyright (c) 2014 Marcus Ihde, Tim Anema

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
]]
local _PACKAGE = string.gsub(...,"%.","/") or ""
if string.len(_PACKAGE) > 0 then
  _PACKAGE = _PACKAGE .. "/"
end
local class = require(_PACKAGE..'class')
local Light = require(_PACKAGE..'light')
local Body = require(_PACKAGE..'body')
local util = require(_PACKAGE..'util')
local normal_map = require(_PACKAGE..'normal_map')
local PostShader = require(_PACKAGE..'postshader')
require(_PACKAGE..'postshader')

local light_world = class()

light_world.blurv              = love.graphics.newShader(_PACKAGE.."shaders/blurv.glsl")
light_world.blurh              = love.graphics.newShader(_PACKAGE.."shaders/blurh.glsl")
light_world.refractionShader   = love.graphics.newShader(_PACKAGE.."shaders/refraction.glsl")
light_world.reflectionShader   = love.graphics.newShader(_PACKAGE.."shaders/reflection.glsl")

function light_world:init(options)
	self.lights = {}
	self.body = {}
  self.post_shader = PostShader()

	self.ambient              = {0, 0, 0}

	self.refractionStrength   = 8.0
	self.reflectionStrength   = 16.0
	self.reflectionVisibility = 1.0

	self.blur                 = 2.0
	self.glowBlur             = 1.0

	self.glowTimer            = 0.0
	self.glowDown             = false

  self.drawBackground       = function() end
  self.drawForeground        = function() end

  options = options or {}
  for k, v in pairs(options) do self[k] = v end

  self:refreshScreenSize()
end

function light_world:refreshScreenSize(w, h)
  w, h = w or love.window.getWidth(), h or love.window.getHeight()

	self.render_buffer    = love.graphics.newCanvas(w, h)
	self.normal           = love.graphics.newCanvas(w, h)
	self.normal2          = love.graphics.newCanvas(w, h)
	self.normalMap        = love.graphics.newCanvas(w, h)
	self.shadowMap        = love.graphics.newCanvas(w, h)
	self.glowMap          = love.graphics.newCanvas(w, h)
	self.glowMap2         = love.graphics.newCanvas(w, h)
	self.refractionMap    = love.graphics.newCanvas(w, h)
	self.refractionMap2   = love.graphics.newCanvas(w, h)
	self.reflectionMap    = love.graphics.newCanvas(w, h)
	self.reflectionMap2   = love.graphics.newCanvas(w, h)

  self.blurv:send("screen",            {w, h})
  self.blurh:send("screen",            {w, h})
  self.refractionShader:send("screen", {w, h})
  self.reflectionShader:send("screen", {w, h})

  for i = 1, #self.lights do
    self.lights[i]:refresh(w, h)
  end

  self.post_shader:refreshScreenSize(w, h)
end

function light_world:draw(l,t,s)
  l,t,s = (l or 0), (t or 0), s or 1 
  local w, h = love.graphics.getWidth(), love.graphics.getHeight()
  util.drawto(self.render_buffer, l, t, s, function()
    self.drawBackground(    l,t,w,h,s)
    self.drawForeground(    l,t,w,h,s)
		self:drawMaterial(      l,t,w,h,s)
    self:drawNormalShading( l,t,w,h,s)
    self:drawGlow(          l,t,w,h,s)
    self:drawRefraction(    l,t,w,h,s)
    self:drawReflection(    l,t,w,h,s)
  end)
  self.post_shader:drawWith(self.render_buffer, l, t, s)
end

function light_world:drawBlur(blendmode, blur, canvas, canvas2, l, t, w, h, s)
  if blur <= 0 then
    return
  end
  canvas2:clear()
  self.blurv:send("steps", blur)
  self.blurh:send("steps", blur)
  util.drawCanvasToCanvas(canvas, canvas2, {shader = self.blurv, blendmode = blendmode})
  util.drawCanvasToCanvas(canvas2, canvas, {shader = self.blurh, blendmode = blendmode})
end

-- draw normal shading
function light_world:drawNormalShading(l,t,w,h,s)
  if not self.isShadows then
    return 
  end
  -- create normal map
  self.normalMap:clear()
  util.drawto(self.normalMap, l, t, s, function()
    for i = 1, #self.body do
      self.body[i]:drawNormal()
    end
  end)

  self.normal2:clear()
  for i = 1, #self.lights do
    self.shadowMap:clear()
    util.drawto(self.shadowMap, l, t, s, function()
      for k = 1, #self.body do
        self.body[k]:drawCalculatedShadow(self.lights[i])
      end
    end)
    self.lights[i]:drawNormalShading(l,t,w,h,s, self.normalMap, self.shadowMap, self.normal2)
  end

  self.normal:clear(255, 255, 255)
  util.drawCanvasToCanvas(self.normal2, self.normal, {blendmode = "alpha"})
  util.drawto(self.normal, l, t, s, function()
    love.graphics.setBlendMode("additive")
    love.graphics.setColor({self.ambient[1], self.ambient[2], self.ambient[3]})
    love.graphics.rectangle("fill", -l/s, -t/s, w/s,h/s)
  end)

  util.drawCanvasToCanvas(self.normal, self.render_buffer, {blendmode = "multiplicative"})
end

-- draw material
function light_world:drawMaterial(l,t,w,h,s)
  for i = 1, #self.body do
    self.body[i]:drawMaterial()
  end
end

-- draw glow
function light_world:drawGlow(l,t,w,h,s)
  if not self.isShadows then
    return
  end

  -- create glow map
  self.glowMap:clear(0, 0, 0)
  util.drawto(self.glowMap, l, t, s, function()
    if self.glowDown then
      self.glowTimer = math.max(0.0, self.glowTimer - love.timer.getDelta())
      if self.glowTimer == 0.0 then
        self.glowDown = not self.glowDown
      end
    else
      self.glowTimer = math.min(self.glowTimer + love.timer.getDelta(), 1.0)
      if self.glowTimer == 1.0 then
        self.glowDown = not self.glowDown
      end
    end

    for i = 1, #self.body do
      self.body[i]:drawGlow()
    end
  end)

  light_world:drawBlur("alpha", self.glowBlur, self.glowMap, self.glowMap2, l, t, w, h, s)
  util.drawCanvasToCanvas(self.glowMap, self.render_buffer, {blendmode = "additive"})
end
-- draw refraction
function light_world:drawRefraction(l,t,w,h,s)
  if not self.isRefraction then
    return
  end

  -- create refraction map
  self.refractionMap:clear()
  util.drawto(self.refractionMap, l, t, s, function()
    for i = 1, #self.body do
      self.body[i]:drawRefraction()
    end
  end)

  util.drawCanvasToCanvas(self.render_buffer, self.refractionMap2)
  self.refractionShader:send("backBuffer", self.refractionMap2)
  self.refractionShader:send("refractionStrength", self.refractionStrength)
  util.drawCanvasToCanvas(self.refractionMap, self.render_buffer, {shader = self.refractionShader})
end

-- draw reflection
function light_world:drawReflection(l,t,w,h,s)
  if not self.isReflection then
    return
  end

  -- create reflection map
  self.reflectionMap:clear(0, 0, 0)
  util.drawto(self.reflectionMap, l, t, s, function()
    for i = 1, #self.body do
      self.body[i]:drawReflection()
    end
  end)

  util.drawCanvasToCanvas(self.render_buffer, self.reflectionMap2)
  self.reflectionShader:send("backBuffer", self.reflectionMap2)
  self.reflectionShader:send("reflectionStrength", self.reflectionStrength)
  self.reflectionShader:send("reflectionVisibility", self.reflectionVisibility)
  util.drawCanvasToCanvas(self.reflectionMap, self.render_buffer, {shader = self.reflectionShader})
end

-- new light
function light_world:newLight(x, y, red, green, blue, range)
  self.lights[#self.lights + 1] = Light(x, y, red, green, blue, range)
  self.isLight = true
  return self.lights[#self.lights]
end

function light_world:clear()
  light_world:clearLights()
  light_world:clearBodies()
end

-- clear lights
function light_world:clearLights()
  self.lights = {}
  self.isLight = false
end

-- clear objects
function light_world:clearBodies()
  self.body = {}
  self.isShadows = false
  self.isRefraction = false
  self.isReflection = false
end

function light_world:setBackgroundMethod(fn)
  self.drawBackground = fn or function() end
end

function light_world:setForegroundMethod(fn)
  self.drawForeground = fn or function() end
end

-- set ambient color
function light_world:setAmbientColor(red, green, blue)
  self.ambient = {red, green, blue}
end

-- set blur
function light_world:setBlur(blur)
  self.blur = blur
end

-- set blur
function light_world:setShadowBlur(blur)
  self.blur = blur
end

-- set glow blur
function light_world:setGlowStrength(strength)
  self.glowBlur = strength
end

-- set refraction blur
function light_world:setRefractionStrength(strength)
  self.refractionStrength = strength
end

-- set reflection strength
function light_world:setReflectionStrength(strength)
  self.reflectionStrength = strength
end

-- set reflection visibility
function light_world:setReflectionVisibility(visibility)
  self.reflectionVisibility = visibility
end

-- new rectangle
function light_world:newRectangle(x, y, w, h)
  self.isShadows = true
  return self:newBody("rectangle", x, y, w, h)
end

-- new circle
function light_world:newCircle(x, y, r)
  self.isShadows = true
  return self:newBody("circle", x, y, r)
end

-- new polygon
function light_world:newPolygon(...)
  self.isShadows = true
  return self:newBody("polygon", ...)
end

-- new image
function light_world:newImage(img, x, y, width, height, ox, oy)
  self.isShadows = true
  return self:newBody("image", img, x, y, width, height, ox, oy)
end

-- new refraction
function light_world:newRefraction(normal, x, y, width, height)
  self.isRefraction = true
  return self:newBody("refraction", normal, x, y, width, height)
end

-- new refraction from height map
function light_world:newRefractionHeightMap(heightMap, x, y, strength)
  local normal = normal_map.fromHeightMap(heightMap, strength)
  self.isRefraction = true
  return self.newRefraction(p, normal, x, y)
end

-- new reflection
function light_world:newReflection(normal, x, y, width, height)
  self.isReflection = true
  return self:newBody("reflection", normal, x, y, width, height)
end

-- new reflection from height map
function light_world:newReflectionHeightMap(heightMap, x, y, strength)
  local normal = normal_map.fromHeightMap(heightMap, strength)
  self.isReflection = true
  return self.newReflection(p, normal, x, y)
end

-- new body
function light_world:newBody(type, ...)
  local id = #self.body + 1
  self.body[id] = Body(id, type, ...)
  return self.body[#self.body]
end

-- get body count
function light_world:getBodyCount()
  return #self.body
end

-- get light
function light_world:getBody(n)
  return self.body[n]
end

-- get light count
function light_world:getLightCount()
  return #self.lights
end

-- get light
function light_world:getLight(n)
  return self.lights[n]
end

function light_world:remove(to_kill)
  if to_kill:is_a(Body) then
    for i = 1, #self.body do
      if self.body[i] == to_kill then
        table.remove(self.body, i)
        return true
      end
    end
  elseif to_kill:is_a(Light) then
    for i = 1, #self.lights do
      if self.lights[i] == to_kill then
        table.remove(self.lights, i)
        return true
      end
    end
  end

  -- failed to find it
  return false
end

return light_world